What Is Silent Magnetic Resistance in an Elliptical Machine?

To adjust the difficulty of an elliptical machine workout, increase the pedal resistance or increase the incline, a feature which is only available on some models. Although most machines offer the option to adjust pedal resistance, the mechanism to do so is not always the same. Silent magnetic resistance is one type of pedal resistance mechanism that has many benefits, but this advanced technology also has a drawback.

Identification

Pedal resistance on an elliptical machine is created via a braking system. Press a button or turn a knob on the console to activate the braking mechanism and create resistance on the flywheel, making it more difficult to move the pedals. This is similar to riding a bicycle with the brakes engaged; the harder you brake, the more difficult it is to pedal. Elliptical machines offer different levels of resistance based on this same braking concept.

Types of Mechanisms

Elliptical machines have one of three types of braking systems, all of which use magnets. The closer the magnet moves toward the flywheel, the more pedal resistance it creates; the farther the magnet moves from the flywheel, the less resistance it creates. Manual resistance systems have a knob on the console. Turn the knob to manually move the magnet. Motorized resistance systems work in a similar manner, but you press a button on the console to activate a motor that moves the magnet. Unlike the other mechanisms, the magnets on silent magnetic resistance systems, also called eddy current braking systems, do not physically move -- they produce a magnetic field, which generates eddy currents and produces friction against the flywheel. The more you ramp up the resistance, the stronger the magnetic field, which results in more pedal resistance.

Benefits

One of the main benefits of the eddy current braking system is the reason it is called silent magnetic resistance. Because there are no moving or touching parts, the mechanism is silent and typically requires little to no maintenance or service. This type of resistance also allows you to change resistance levels more quickly than other systems because it does not depend on parts moving through physical space, which takes time.

Drawback

The largest drawback to the silent magnetic resistance system is the price tag of the machine. Because it is the most sophisticated type of braking system, only higher end, more expensive elliptical machines have silent magnetic resistance. Less expensive systems have manual or, more commonly, motorized resistance. Elliptical machines with silent magnetic resistance systems are found in commercial gyms and fitness centers, but are also available on in-home machines.